{stdenv, fetchurl, static ? false}:
stdenv.mkDerivation {
name = "zlib-1.2.3";
src = fetchurl {
url = http://www.zlib.net/zlib-1.2.3.tar.gz;
md5 = "debc62758716a169df9f62e6ab2bc634";
};
configureFlags = if static then "" else "--shared";
# zlib doesn't like the automatic --disable-shared from the Cygwin stdenv.
cygwinConfigureEnableShared = true;
}